Glue applicator for panel patching machine



March 11, 1969 w. E. WARREN 1,

GLUE APPLICATQR 'FOR PANEL PATCHING MACHINE Filed Dec. 4, 1967 Sheet of 2 FIG. 1

WILLIAM E. WARREN INVENTOR BUCKHORN, BLORE, KLARQUIST & SPARKMAN ATTORNEYS March 11, 1969 w. E. WARREN 3,

GLUE APPLICATOR FOR PANEL PATCHING MACHINE Fild Dec. 4, 1967 Sheet 2 of 2 FIG. 4

WILLIAM E. WARREN INVENTOR BUCKHORN, BLORE, KLARQUIST & SPARKMAN I ATTORNEYS United States Patent 3,431,888 GLUE APPLICATOR FOR PANEL PATCHING MACHINE William E. Warren, Beaverton, Oreg., assignor to Western Machinery Corporation, Portland, Oreg., a corporation of Oregon Filed Dec. 4, 1967, Ser. No. 687,690

US. Cl. 118238 13 Claims Int. Cl. Bc 1/02 ABSTRACT OF THE DISCLOSURE A glue applicator for a panel patching machine wherein a rotatable glue roll carried by a glue reservoir mounted on the frame of the machine is supplied with motive power through the horizontal movement of a carriage on the machine which carries recess routing and patch inserting tools. The glue roll is mounted for downwardly pivoting movement in the reservoir against spring pressure so as to effectively coat with glue patches of slightly different thicknesses moved across the roll by the carriage.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to machines for forming recesses in wood panels to remove surface defects and for inserting wood patches in such recesses, and more particularly to a glue applicator for such a machine for applying glue to each patch prior to its insertion in a recess.

Description of the prior art Prior glue applicators have included rolls which were rotated continuously by a drive motor which was independent of the primary source of motive power for the other machine elements. Moreover, the rolls of prior glue applicators have been fixed against self-adjusting vertical movement within the glue reservoir, thereby coating patches of slightly different thicknesses with differing amounts of glue and being particularly subject to malfunction.

Summary of the invention The present invention provides a glue applicator which requires no independent source of power for driving the glue roll and in which motive power for driving the glue roll is supplied solely by movement of the tool carriage of the machine.

The present invention furthermore provides a pivotally mounted, spring loaded glue roll which can pivot downwardly to accommodate patches of different thicknesses.

Additional features of the machine include (1) a glue roll assembly which can be removed quickly and easily from the glue reservoir for cleaning and servicing without removing or loosening any screws or bolts; (2) a glue roll drive including gearing with features which prevent jamming and which provide the gears with self-cleaning attributes; and (3) a glue roll drive which rotates the glue roll intermittently only during the cutting stroke of the tool carriage.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying drawings wherein:

FIG. 1 is a front view of a panel patching machine incorporating a glue applicator and drive mechanism in accordance with the invention;

FIG. 2 is a fragmentary plan view on an enlarged scale taken approximately along the line 22 of FIG. 1 showing the glue applicator and glue roll drive;

FIG. 3 is a vertical sectional view taken along the line 33 of FIG. 2;

FIG. 4 is a plan view of the glue reservoir of FIG. 2 with its cover partially broken away and on a scale twice that of FIG. 2;

FIG. 5 is a vertical sectional view taken alOng the line 55 of FIG. 4;

FIG. 6 is a vertical sectional view taken along the line 6-6 of FIG. 4;

FIG. 7 is a fragmentary axial section through a portion of the grooved glue roll surface on a scale greatly enlarged from that of FIG. 4; and

FIG. 8 is a fragmentary cross-sectional view through a surface portion of the glue roll containing an axially extending groove.

DETAILED DESCRIPTION General arrangement With reference to the drawings, FIG. 1 illustrates somewhat schematically a plywood panel patching machine 10 of the type disclosed in US. Patent 3,129,736 issued Apr. 21, 1964 in the name of E. A. Herman, and reference is made to such patent for a description of the details of construction and operation of such machine. However, in general the machine includes a work table 12 which supports a plywood panel P to be patched, a frame 14 overlying and adjustable vertically relative to the table, and a carriage 16 movable horizontally above the panel on guide rails 18 of the frame by a fluid powered cylinder 20 stationarily mounted on the frame. The carriage carries a vertically movable router 22 including a cutting element 24 which is moved into the panel P a predetermined distance corresponding to the thickness of a patch when the carriage moves toward the right in FIG. 1 to begin the router cutting stroke which forms an elongate recess in the panel. The carriage also carries a vertically movable vacuum head 26 which picks up a patch 27 from a pickup station 28 on a platform portion 30 of the frame when the carriage is in its extreme left hand position of FIG. 1. Patches are supplied singly to the pickup station from a patch magazine 32 by a delivery mechanism (not shown).

When the carriage starts its movement toward the right in FIG. 1 from its extreme left hand position after the vacuum head has picked up a patch, the router cutter is lowered into the panel to cut a recess, and at the same time the vacuum head carries a patch over a glue roll 34 supported by a glue reservoir 36 mounted on one side of the platform 30 of the frame to apply glue to the underside of the patch. The reservoir mounting means comprises a dovetail key 38 on the reservoir which slides within a slot on the platform, and a toggle clamp 39 which secures the reservoir against sliding movement. The carriage continues its movement toward the right until a recess of the desired length has been formed in the panel, after which the carriage is stopped and the router withdrawn from the panel. Thereafter the carriage continues its travel toward the right until the patch on the vacuum head is directly above the panel recess, whereupon the carriage is stopped and the patch inserted into the recess by downward movement of the vacuum head.

Glue applicator Referring to FIGS. 2, 4 and 5, the gluereservoir 36 has a cover 40 which permits only the glue roll to project through an opening therein so that wood chips are prevented from entering the glue. The cover is shown mostly broken away in FIG. 4 for clarity of illustration.

3 Glue roll 34 is mounted on a roll shaft 42 between a pair of arms 44, 45 of a pivot bracket 46 which rotatably support the roll shaft. The rear ends of bracket arms 44, 45 have upwardly opening recesses 4-8 which receive the opposite ends of a pivot shaft 50. Pivot shaft 50 is fixed by a roll pin 51 within a pivot anchor block 52 secured to an integral riser portion 54 of the reservoir by Allen head screws 55. A bolt 58 projects upwardly through a central bottom portion of the reservoir and through a rearwardly opening slot 60 in a web portion 62 of the pivot bracket. A coil compression spring 64 surrounds the bolt below the web 62 and extends between the web and the bottom of the reservoir to urge the pivot bracket upwardly against a stop nut 66 threaded onto the bolt above the web. The stop nut determines the upward adjustable limit of pivotal movement of the bracket about pivot shaft 50 and thus the normal level of the glue roll.

The aforedescribed mounting of the pivot bracket affords ready removal of the entire glue roll assembly, including the bracket, from the reservoir simply by pressing down on the bracket against the force of spring 64 until the bracket arms are disengaged from the pivot shaft, whereafter the bracket arms can he slipped from beneath the pivot shaft and the bracket and roll assembly removed intact forwardly and upwardly from the reservoir without removing or loosening any bolts or screws.

A scraper plate 68 is secured to the upper surface of web 6 2 by screws 69 extending through rearwardly opening slots 70 of the scraper. This permits sliding adjustment of the blade portion 72 of the scraper toward and away from glue roll 34, whereby the quantity of glue carried by the roll can be accurately controlled.

The glue roll itself is made of a noncorrosive metal such as brass. The roll surface comprises a series of circumferential, parallel grooves 74 interrupted periodically by lateral concave grooves 76 shown in cross section in FIG. 8. The circumferential grooves have inclined sidewalls as shown in FIG. 7, with one sidewall 77 inclined at an angle of about 20* degrees and the opposite sidewall 78 inclined at an angle of about 40 degrees. The foregoing groove pattern provides for the pickup of a metered amount of glue and even distribution of such amount throughout the roll surface. Parallel rather than spiral circumferential grooves resist any tendency of the roll to shift a patch on the vacuum head when engaging such patch.

Glue roll drive Referring to FIGS. 2 and 3, glue roll 34 is driven so that the upper surface of the roll rotates in the direction of movement of a patch across such surface and at a surface speed that is equal to the linear speed of the patch so that glue is applied to the patch in a uniform layer and without relative skidding of the roll and patch. The glue roll drive is unique in that no motive power is required other than that required to slide the carriage horizontally. That is, motive power for rotating the glue roll is supplied solely by the carriage movement. To this end, a rack gear 80 is secured to the lower carriage bosses 82 which receive one of the guide rails 18 so that the rack moves with carriage 16. The rack engages a drive pinion 84 carried by a pinion shaft 86 mounted on a support bracket 88 secured to the main frame 14. Pinion shaft 86 also carries a drive pulley 90 about which a timing belt 92 is trained. Belt 92 extends to and is trained about a driven pulley 94 carried by an input shaft 96 of a speed change unit 97 which is normally shielded but shown unshielded for clarity. The unit includes driven gear 98 on shaft 96, which is supported by a bracket 100 secured to a side of frame platform 30. Driven gear 98 engages the slightly smaller driven gear 99 carried by shaft 102, which is also supported by bracket 100. Shaft 102 is in alignment with an input shaft 104 to the glue reservoir and carries a coupling element 106 for drivingly connecting the two shafts together.

With reference to FIG. 4, the inner end of shaft 104 mounts a spur gear 108 which in turn engages a spur gear 110 on the projecting end of roll shaft 42. Thus carriage movement in a direction toward the right in FIG. 1 results in the transmission of motion through the rack on the carriage, the drive pinion, belt and pulleys, driven speed up gears and spur gears to the roll shaft, which rotates the glue roll in the predetermined direction and at the desired speed, which is related to the speed of travel of the carriage in the previously described manner. Drive pinion 84 is a one-way form sprag gear mounted so that it rotates the pinion shaft and thus drives pulley 90 only when the carriage moves toward the right in FIG. 1; that is, only during the cutting stroke of the carriage and not during its return stroke.

As viewed in FIG. 6, the geometrical interrelationship of the rotational axes of spur gears 108, 110 and the axis of pivot shaft 50 is such that the pivot bracket can pivot downwardly from its spring-biased position, despite the engagement of the spur gears. Furthermore, any excessive downward pivoting movement of the pivot bracket, such as might be caused by the presence of two patches on the vacuum head or by chips or other foreign matter between the gear teeth, will momentarily disengage the spur gears until the difiiculty can be rectified, thereby avoiding jamming of the gears or other damage to the machine. The same geometry causes the driving torque of spur gear 108 to urge the driven gear 110 upwardly into positive driving engagement with spur gear 108 when spur gear 108 is driven in a direction to rotate the upper surface of the glue roll in the direction of patch travel. If spur gear 108 were driven in the opposite direction, it would tend to drive engaged spur gear 110 downwardly out of mesh, thus tending to cause slippage between the spur gears when downward pressure is applied to the glue roll.

In general, pivot bracket 46 is adjusted by nut 66 so that the spur gears will not jam and so that the level of the upper surface of the glue roll will be slightly above the bottom surface of a patch carried b the vacuum head. With the roll so adjusted, a patch of normal thickness will exert a positive downward pressure on the roll when traveling over its surface, thereby forcing the pivot bracket downwardly a very slight amount. Such an adjustment will enable the glue roll to accommodate and coat adequately patches of the same nominal thicknesses but slightly different actual thicknesses. In practice, patches of the same nominal thickness can vary up to of an inch in actual thickness. Normally the glue roll level would be adjusted so that a normal patch would not force the roll to pivot downwardly more than about of an inch.

Having illustrated and described what is presently a preferred form of the invention, it should be apparent to those skilled in the art that the same permits of modification in arrangement and detail. I claim as my invention all such modifications as come within the true spirit and scope of the following claims.

I claim:

1. In a panel patching machine including a frame, patch holding means for picking up, holding and inserting a patch in a recess within a panel to be patched, and carriage means mounting said patch holding means and movable horizontally for transporting said holding means from a patch pickup station to said recess,

glue applicator means including a glue reservoir and a glue roll mounted for rotation within said reservoir,

means mounting said reservoir in such a position on said frame that horizontal movement of said carriage from said pickup station to said recess will carry a patch on said holding means into surface contact with said glue roll, and

glue roll drive means for rotating said glue roll including motion transmitting means drivingly interconnecting said carriage means and said glue roll in a manner such that horizontal movement of said carriage in a direction from said pickup station toward said recess effects rotation of said glue roll.

2. Apparatus according to claim 1 wherein said motion transmitting means rotates said glue roll in a direction such that the patch-engaging surface of said roll moves in the direction of travel of said patch and at the same linear speed as said patch during said carriage movement.

3. Apparatus according to claim 1 wherein said motion transmitting means includes a gear rack means on said carriage means and pinion gear means engaging said rack means and supported independently of said carriage means.

4. Apparatus according to claim 1 wherein said motion transmitting means includes a gear rack on said carriage means, pinion gear means supported independently of said carriage means and engaging said rack means, roll shaft means mounting said roll, driven gear means on said shaft means, and interconnecting means drivingly interconnecting said pinion gear means and said driven gear means.

5. Apparatus according to claim 4 including means mounting said roll and roll shaft means for limited vertical movement while said driven gear means remains drivingly connected to said pinion gear means.

6. Apparatus according to claim 5 including means urging said roll shaft means and roll into an upper limit position, said driven gear means on said roll shaft being so related to said interconnecting means that downward movement of said roll shaft means beyond predetermined limits disengages said driven gear means from said interconnecting means.

7. Apparatus according to claim 4 wherein said interconnecting means includes belt and pulley means, and speed changing means.

8. Apparatus according to claim 4 wherein said pinion gear means includes means for disengaging said pinion gear means from said interconnecting means during horizontal return movement of said carriage means from a recess to said patch pickup station.

9. Glue applicator means including work holder means for holding in depending fashion Work to be coated with glue, a glue reservoir, a glue roll, Work transporting means for moving said work holding means generally horizontally relative to said roll whereby work is moved into surface contact with said roll, mounting means urging said roll to an upper limit position and resiliently mounting said roll for vertical movement within said reservoir upon contact of the roll with the work to provide for varying thicknesses of work, and drive means interconnecting said transporting means and said roll whereby movement of the work transporting means toward the roll elfects rotations of the roll.

10. Apparatus according to claim 9 wherein said drive means and said mounting means being interrelated in a manner so that said drive means continues to rotate said roll during limited downward movement of said roll from its upper limit position but so that said drive means drivingly disengages said roll upon downward movement of said roll beyond predetermined limits.

11. Apparatus according to claim 9 wherein said mounting means includes a roll shaft, pivot bracket means rotatably mounting said roll shaft, a pivot shaft engaging said pivot bracket means within upwardly opening slots in said bracket means rearwardly of said roll shaft, means mounting said pivot shaft within said reservoir, spring biasing means urging said bracket means and thereby said roll to an upper limit position, and adjustment means in association with said biasing means for adjusting the vertical level of said roll within said reservoir.

12. Apparatus according to claim 11 wherein said biasing means includes a vertical shaft means extending upwardly from the bottom of said reservoir and through a rearwardly opening slot in said bracket means longitudinally between said pivot shaft and said roll shaft, and coil spring means encircling said vertical shaft means between said bottom and said bracket means, said adjustment means comprising a nut means threaded onto said vertical shaft means above and in engagement with said bracket means, whereby the bracket and roll assembly can be removed from said reservoir by depressing said bracket against said spring means until said bracket means disengages said pivot pin, and then sliding said bracket means forwardly from engagement with said vertical shaft means.

13. Apparatus according to claim 1 wherein said drive means includes means for rotating said glue roll intermittently only during carriage movement in a direction toward said recess.

References Cited UNITED STATES PATENTS WALTER A. SCHEEL, Primary Examiner.

ROBERT I. SMITH, Assistant Examiner.

U.S. Cl. X.R. 1442; 156514 

